During vibratory compaction of asphalt with a vibratory plate, the underside of the base plate is continually wetted to avoid the adhesion of asphalt. Water is normally used for this wetting, however, emulsions can also be used. On page 13 of the manual: “Mikasa SERIES MODEL MVC-88GH/GHW ONE-WAY PLATE COMPACTOR”, “Revision #4 (Oct. 15, 2004)”, a vibratory plate is shown with a sprinkler device. The base plate (position 7) of the vibratory plate is provided with a channel at the front (position 9, “splash plate”), with a length along the front edge of the base plate. The length of the channel is discontinued in the middle by an protruding eccentric housing (position 8). The water tank (position 11) of the sprinkler device has an outlet at the bottom (position 9, “water tube”) which is arranged for release of water to both sections of the channel and for release in the middle on the protruding eccentric housing. The total opening area for the outlet is in this case allocated to a minimum of three openings, and therefore the separate opening areas are very small. This can cause the outlet to become very easily blocked by impurities in the water. In such circumstances it is complicated to flush the outlets without extensive dismantling. The sprinkler device basically corresponds with the device shown in the U.S. Pat. No. 6,379,082. In FIG. 2 of this patent, it is shown how the outlet can be opened and closed with a valve 15. The knob of the valve is connected to the valve and is placed at the same level as the bottom of the tank. From an ergonomic point of view this is not a good position for the knob because the operator has to bend down a long distance to reach the knob. There is a considerable risk that the operator will operate the valve by kicking the knob instead of bending down and in so doing damage the knob or adjacent components. The positioning and execution also make it difficult for the operator to regulate the quantity of water released. There is a considerable risk that the operator will not regulate the quantity of the water to be released to what is actually needed and will instead open the valve completely. The result of this is that an unnecessary amount of time must be used to refill the tank with water.